Abstract

In this paper, the AA. argue that the formation of low-relief surfaces over areas of large extent and cutting across bedrock of different age and resistance must have been guided by distinct base levels. The AA. have analysed West Greenland landscapes by combining the cooling history from apatite fission-track analysis (AFTA) data with the denudation history from landscape analysis and the stratigraphic record. An important difference between their approach and that of classical geomorphology is that they now have the ability to document when thick sections of rocks have been deposited and then removed. The present-day high-level plateau in West Greenland is the remnant of a planation surface. Here the AA. present additional AFTA data to show that the planation surface is the end-product of Cenozoic denudation even in basement areas and argue that Phanerozoic sediments must have been present prior to denudation. They suggest that other margins with similar morphology may also be characterized by episodic post-rift uplift unrelated to the processes of rifting and continental separation, rather than being permanently uplifted since the time of rifting, as is commonly assumed